The 28-year-old former football standout was found dead June 1 on a city sidewalk in the 2100 block of McMinn Street. Officials determined the cause of death was a single gunshot wound to the head and neck.

Police have not released information about individuals interviewed in the case, but Couch said the investigation is ongoing. As for police having narrowed down a suspect, Couch said, “Yes, absolutely.”

Before making an arrest, Couch said the department is focused on making sure prosecutors have enough information and evidence to get a conviction.

“If we’re going to file, we want to make sure we’re going to win this thing,” he said.

A lot of legwork has gone into the investigation, including collecting evidence, conducting ballistic tests and sending relevant items for testing. While investigators have run into some dead ends, Couch believes the potential to solve the case is still there.

“(Detectives) have since been developing new stuff to follow up on,” Couch said. “I have faith that, between our detectives and the Beaver County district attorney’s office, we will make an arrest in that case.”

Beyond their belief that the case can be solved, police have not released specific details about the investigation.

“When we go into an interview room, we’re comparing (those case facts) against if should this person know these facts,” Pudik said.

Gilliam’s known past offers little clues into the incident, and police have not confirmed a motive for his death.

While serving as a U.S. Marine in 2009, Gilliam earned a Purple Heart after he suffered a head injury from a roadside bomb in Afghanistan. He recuperated in a German hospital for two weeks and lost some hearing in his right ear.

According to his obituary, he received several other accolades during his time in the Armed Forces, including a second Purple Heart, the Global War on Terrorism Expeditionary Medal for his time in Afghanistan and the Global War on Terrorism Service Medal.

After returning to Aliquippa, Gilliam had two run-ins with the law, though he was never convicted of a crime. In 2010, he was charged by Aliquippa police with misdemeanor counts making terroristic threats, disorderly conduct and public drunkenness — all of which were withdrawn.

Gilliam was arrested again in November 2015 after police found a stolen firearm in his car during a traffic stop. He was charged by Aliquippa police with receiving stolen property and carrying a firearm without a license, both felonies. He died before facing trial.

While juvenile records aren’t public information, Couch said prior to Gilliam’s return from the Marine Corps, he was only known only for his success as a high school football player.

“He was a great football player, good quarterback, you know,” Couch said. “That’s it. No problems at all.”

Neither Couch nor Pudik recall any sort of public homecoming celebration when Gilliam returned to Aliquippa after serving in Operation Enduring Freedom.

“That would not have been him,” Pudik said, recalling Gilliam as a “very private individual.

Other than family and a “select group of friends,” Gilliam didn’t “allow many people to get close to him, from my experience with the case,” Pudik said.

Nevertheless, his death garnered national interest.

“We’ve had CNN call; we’ve had everybody call,” Pudik said. “But when you have a case like this, you have to balance what we can release and what we can’t release.”

In a year marred by four shooting city deaths, police look to Gilliam’s death as “the odd ball out,” Pudik said.

In other recent cases, the community has cooperated in investigations, he said.

“Most of the time in Aliquippa we have good participation with the community in solving crimes,” Pudik said. “(This case) is a little different because we know that there are people who know details about the case, and they have yet to come forward.”

Couch also believes there are people with relevant information for police and is hopeful that new details will eventually come to light.

“Obviously, we still would love to have anybody that knows anything about it contact us,” Couch said. “They might think we know, and we don’t, or they may add a particular detail that was not mentioned. We urge people to do that.”

In the four months after Gilliam’s death, the Aliquippa Police Department was tasked with investigating three more homicides: Dre’Von Jackson, William Cade Booher and Dane Mathesius. Arrests have been made in each death.

Pudik believes the violence of 2016 has impacted the community.

“I think that perhaps the tragedies of last year … made an impact on the community, he said. “I think it probably reminded people of what can happen and what has happened.”

Authorities are asking anyone with information about Gilliam’s death to call Aliquippa police at 724-375-6682 or the district attorney’s office at 724-773-8550.